The present invention relates to keyboard printed circuit films and, in particular, such a film comprising switching contact points which are connected in groups to terminal contact points via conductor strips printed on the film, and having means for reducing the coupling capacitance normally presented between adjacent conductor strips where they lead to terminal contact points.
In such keyboard printed circuit arrangements, it is common that two films whose switching contact points are congruent are opposite to each other. Keys are arranged above these switching contact points, and the actuation of these keys leads to contacting of the respective switching contact points.
The conductor strip material which is conventionally utilized has been found to have low resistance to effects occurring during operation in the area of the terminal contact points and of the switching contact points. The terminal contact points and/or the switching contact points are therefore often made from a carbon resistor layer which is substantially more resistant to the stresses occurring during operation. However, coupling capacitances develop between the conductor strips in such printed circuit films. These capacitances frequently exert disturbing effects on the electronic circuit connected to them.